Molded pulp carton press



June 2, 1953 A. E. coMsTocK 2,540,401

MOLDED PULP CARTON PRESS I June 2, 1953 A. E. coMsTocK 2,640,401

` MOLDED PULP CARTON-PRESS Filed Sept. 9, 1950 5 sheds-sheet 2 f6 I l l fa 4f fa l I IN VEN TOR.

June 2, 1953 A. E. coMs'rocK 2,640,401

MOLDED PULP CARTON PRESS Filed Sept. 9, 1950 5 Sheets-Sheet 5 IN V EN TOR.

June 2, 1953 A. -EQcoMsTocK 2,640,401

MOLDED PULP CARTON PRESS Filed Sept. 9, 1950 5 Sheets-Sheet 4 IN VEN TOR.

WM m Ws 7%# June 2, 1953 A. E. coMsTocK 2,640,401

MOLDED PULP CARTON PRESS Filed Sept. 9, '1950 5 Shets-Sheet 5 INVEN-ToR.

' a BY WwW/WW Patented .une 2,

MOLDED PULP CARTON PRESS Alfred E. Comstock, Palmer, Mass., assignor to Shellmar Products Corporation, Chicago, Ill., a

corporation of Delaware Application September 9, 1950, Serial N o. 183,945

This invention relates, generally, to apparatus for pressing molded pulp articles, such as egg cartons, after they have been molded and dried, for the purpose of squaring up such articles and giving a smooth ironed or calendered finish thereto.

When molded pulp articles such as egg cartons are made in accordance with the conventional manner in which a layer of pulp is formed over a foraminous die or screen and the wet molded article is passed through a drier, the dried ar` ticles will usually not be exactly square or true to shape and their surfaces will have a rough nish. According to the present invention I have found a practical apparatus and method for pressing the dried molded pulp articles as they are stripped and discharged from the molding apparatus so as to give the articles a smooth calendered or ironed finish and also to right or square up the articles and take out any warpage or distortion which may have set in during drying.

An important object of the inventionV is the combination of a finishing press with gravity delivery chutes leading from a pulp molding ma- `Jhine.

An object of the invention is to hot-press dry molded pulp articles so as to impart a nished surface thereto and also to square up the articles as they are discharged through included chutes leading from the stripper of an automatic type molded pulp article making machine to a conveyor for removing the iinished article away therefrom.

Another important object of the invention vis the combination of an automatically controlled press for dry molded pulp articles, such as egg cartons, as they are discharged through a chute leading from a stripper of an automatic type pulp molding and drying machine to a conveyor leading away therefrom, the press being operatively interconnected with the molded pulp article making machine and the control gates of the discharge chute so that the operation of the press is synchronized with that of the article producing machine.

Still another important object of the invention is an automatic type finishing press for righting up and surface-finishing molded pulp articles, such as egg cartons, which is adapted to be installed in a discharge chute for the molded pulp articles and to be controlled by the apparatus which delivers the molded pulp articles into the chute.

Another important object of the invention is 6 Claims. (Cl. 92-68) an automatic type hydraulic press for squaring up and surface-iinishingmolded pulp larticles which has male and female dies which are normally separated and at least'one of Vwhich is movable relative to the other, wherein there are reciprocally operating article receiving guides adapted to be inserted as a section `of a gravity type discharge chute for the molded pulp articles and to support each article as it passes through the chute until the press is closed sufficiently to support the article whereupon the support guides are withdrawn when the dies are closed and then returned to their article supporting position to support the article after the press is opened and the pressed article has been discharged from the dies.

Certain other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof taken in connection with the accompanying drawings,vwherein:

Fig. l is an elevational view, partly broken away, showing a molded pulp article finishing press made in accordance with the present invention and combined with a Agravity feed discharge chute leading from the stripper of an automatic type molded pulp article making machine to a conveyor for removing the finished articles therefrom;

Fig. 2 is a side elevational view on enlarged scale of the press shown in Fig. 1 with certain parts of the press shown in a different position of operation;

Fig. 3 is an elevational view of the press take from the left-hand siderof Fig. 2;

Fig.4 4 is a view corresponding to Fig. 3 but showing therelaticnship of the parts when the press is closed; y

Fig. 5 is a diagrammatic view showing the control mechanism for the molded pulp article nishing press of Fig. l;

Fig. 6 is a fragmentary top plan view taken along line of Fig. 2 and showing the latching mechanism for the upper die block of the press;

Fig. 7 is a fragmentary elevational view of the latching mechanism shown in Fig. 6; and

Fig. 8 is a fragmentary sectional view on enlarged scale taken online 8 8 of Fig. '7.

` Referring to the drawings, in Fig. 1 a finishing press isrindicated, generally, at 5 which forms one embodiment of the present invention and' 3 which is combined with and positioned in a gravity feed egg carton discharge chute, the upper section of which is indicated at 6 and the lower section of Which is indicated at 1. This discharge chute corresponds to any one of the discharge chutes 6i described in my copending application Serial No. 134,229 led December 21, 1949. The upper section G of the chute leads from a carton stripper (not shown) such as the stripper forming the subject matter of my copending application. Such a stripper serves toY strip dry molded pulp egg cartons.Y ofV the type shown in U. S. Patent No. 2,455,295 from an automatic apparatus for forming such articles, in: cluding pulp molding equipment andaarticlefdry.- ing equipment. Molded pulp egg cartons 8 fall by gravity through the discharge clnite5 and are.. discharged by the bottom section upona con veyor mechanism indicated at It which leads to.

equipment for printing and stacking the finished aTzFCSf njost: molded pulp machines, a plurality of articlesfwillbe vfo'rn'iexrzl simultaneously across the 1 t.. the machine. Accordingly, there Will be ainumber''ci parallel discharge chutes leading fronizthestripper onto the conveyor iii, and in eac fof thesechutes an automatic type finishing pi 'Will Vbe positioned. The arrangement sh wn in Fig. l can thus be duplicated as many required, depending upon the numbe of discharge chutes for a particular installation.

(While: theegg cartons 8( are formed and st dat. aruniiorm rate, there may be some vereine iii-their timing. and in. Order w control the release of the cartons lthrough the discharge chute, particularlywherethere are a plurality` of suh chutes. a gate isV provided in the upper section 6 of each chute. This gate is operated in synchronisinwith the stripper andWith the gates herchutes. For example, in Fig. i such a idicated at Ii in broken line and is op. @Die ville.. Stripper. byV means f a Gonnctig rod i2. Referringto my aforementioned eeefiineapbliein ASerial No. 134,229, the gate l1!" co respgndstoone of the gates or dogs desthat'applc'ation by the reference nu ngeraljie and the connecting rod or operating member ,-4.21c9rreispones to one` of. the connecting tvIillWloed understood that the connecting rod i2 is reciprocated at a rate`Y corresponding to'5 the rate at which the egg cartons ai? nd-discharged into the chute sec- In Fig. 1, the gate l! takes the form of an elongated member havingI a projection is on the bttin 'end anda projection I4 on theupper end. The? gatefl l vfis .supported on a pin l5 to Whichtheefis also connected a bell crank lever i6." The 'bottom end lof the connecting rod i2 is piytalls connected at H tov one arm of the bell nkiveir' 'ite-'ndice other arm, thereof is `pivotallyconnected at` lto a lever 2B which serves tomoperatethe trip mechanism for lowering the testop theegg cartons at the right p o Within the press 5, as Will bev more fully described below.

Each egg carton- 8: passing through the discharge chute is normally stopped in the press 5 and theipress thenoperates automatically to close male andvfemale die members, at least one otwhichfis preferablyfheated, so as to impart a sz'n'otlifiroried orffcalendered iinishv to theuegg. ae'dlso :idealista-1P ausmachen out so deeignated-and referred to in said ap-L f any distortions or Warps therein. Thereupon, the press is automatically opened and the nished article permitted to drop by gravity through the chute section 'l and onto the conveyor iii.

The press 5 is supported on a suitable frame structure which is indicated generally at 2 l The details of. the frame structure `2i are not important in so faras the present invention is concerned and a detailed description of the frame Will not be given.

The mainstationary parts of the press 5 comprise a middle block 22, a top block 23, and a bottom block-2&1. Theseiblocks are secured together in their respective spaced relationships by a pair of. side plates` 25-25 as shown in Figs. 3 and 4 which are bcltedtothe blocks in known manner, as shown. Preferably, the blocks E2, 23 and 2li areinithe form of castings in which the proper openings and cavities are formed.

Thelblocks 22; 23 andi-5 are risidivsnpported from the frame 2.1 in; e Suitable and. thevarious moving parts-ot thepress larepreperly assembled and supported ior-movmgnt on the stationary parts.` The pressishydraulical: ly operated by means of a hydraulic cylinderz attached i@ the bottomrbloelegfc Toeristen-rod of the cylinder 2751s, connected, are@ ou .r en with a cross head 2l to which two'- line Y 8f-2:8 of'a toggle mechanisrn` are-pivotallycen cted as ndicatedwat Eil-3i). Eachof the'links, pivotally connected aia-3l tocagpa'ireoi. toggle links 32E-32 and eachfset ofthe linggle.v linksV S25-32 is pivotally connected on one endgtogaustationary pin S3, and on the; O 'her en d; to aY pl` sfzl'd 0n ears 555-35- proietine from. the'boitom of a block 36. The purpose of the, toggle linkage mechanism is to multiply the lforce;delvi'v'lilfgd,by the hydraulic cylinder 2e and thereby; reduce the size of the cylinderl required,

ItWill be understoodgthat as. the piston of the hydraulic cylinder 2G is forced outwardly-so as to thereby :nove the headvvZ'iupWardly, the toggle linls.v 32e-32 are. straightenedsomewhat and the block it is forced upwardly adistance. somewhat less than the distance moved bythe piston of the hydraulic cylinder A26,. anddependent upon the mechanical advantage cfg-the toggle lnks.- The bleek 3 Seri/ esto Support-atweber: ners thereof foul rods 31,-31 Vwhich carry;- on their, upper ends a glck 3.8.,Sunp0rtineftbe :maiedie` fl- (Fig. 2) of the press 5. Each ofthe fourv rods 3l isthreaded at opposite endsandeaclg rod is secured at the lower end to one ofgthe corners oi the-,blockv 3B by-meansgof apair of nuts ill-M drawn up tighten oppesite-sidesthereof. The upper threaded endsn oftherodsflproj ect` through openings provided thereforY the blocki',l and nuts 42e-l2V are tightened id ofvvnL thereon to prevent the threaded ends; from, pullfV ing @utf The wis 3i proj@Qtr-aridv S1 i.de;thr,ouehi transverse openings t@ DrQYiQedthereQxsinf the ,Stationary block; 22a-ond. also. tbrocenahclesv rial-i5 provided therefor inra movableblock A5' connected to thestationary block. 22by aplurality of connecting bolts lle-.ediilig 2).. The boltsv ilfproject through the. central` web Alsof the blockandthe lower ends thereofyare pro. vided with nuts iB-48- vwhichY bear against-the bottom of the web 4l. Thebolts.,paresurg rounded. for the mainwleneths thereof, :-byfcom:A pression, springs ,r-- f Thefbottcmende.czffthel springs 59am-supported 0n ,the .tons fagoff the web #l while the upper ends of the-sp the movable block 45. The bolts 46 project beyond the top of the block 45 and the heads 5 I-5I are accessible from holes 52-52 formed in the block 38 as shown in Fig. 2.

During the upward movement of the block 38 carrying the male die 40, the compression springs 50 cause the block 45 to follow the block 38. However, after a predetermined upward movement of the block 45 has been completed, the bolt heads 5l arrest its further movement while block 38 continues its upward movement until the press is fully closed.

The male die 40 is provided with a series of carton lifting tappets 53-53 (Fig. 2), the heads of which are situated in the bottoms of the pockets or valleys formed in the top side of the male die 48 as shown. There may be as many as I6 of these spring-loaded tappets 53 which extend downwardly through the block 38 and the lower heads 54 of which press against the top face of the block 45. The bottom ends of the tappets 53 are surrounded by compression springs 55-55 which it in countersunk recesses 56-56 provided therefor in the bottom of the block 38 and which are compressed between the top end of these recesses 55 and the upper sides of the heads 55. The tappets 53 are vertically reciprocable and when the block 58 is separated from the block 45, the compression springs 55 serve to press downwardly the heads 54 of each of the tappets, thereby retracting the upper end of the tappet to a seated position in the face of the male die 40. However, when the block 38 is brought down against the block 45, the tappets 53 will each be lifted or projected from its retracted or Seated position as the bottom ends 54 engage the top of the block 45.

In order to guide egg cartons into the press 5 and to support them before the press is closed and again after the press is opened, a pairof reciprocable carton supports or side rails 51-51 are provided each of which is carried on the upper ends of one of two sets of arms 58-53.

Each of the swingable arms 58 is provided with an integral hub Si) (Fig. 2) on the bottom end thereof which pivotally ts over a support pin therefor projecting from the side of the stationary block 22. Each of the arms is provided midway between the ends thereof with a roller 6l which serves as a cam follower to follow a cam groove or cam track 62 provided in each one of a set of four members 63-63 having plate portions 64 by which they may be bolted to the sides of the movable block 38 as shown, for example, in Figs. 3 and 4. When the head 38 is in its lower or retracted position, the members 63 are correspondingly lowered and the cam slots or tracks 52-62 are so shaped as to cause the arms 58--58 to swing inwardly so as to move the rail members 5l toward each other and into a carton supporting position as shown, for example, in Fig. 3. In this position the guides or rail sections 51 form extensions of the discharge chute sections 6 and 1. When the press 5 is closed and the head 38 is raised, the cam followers or rollers 6I will be shifted outwardly and the arms 58 will also be swung out as shown, for example, in Fig. 4 in which position the guides 5'1-51 no longer support an egg carton and do not interfere with the final closing together of the die members with an egg carton positioned therebetween.

The female die 65 is carried on a cover block 66 which is pivotally mounted adjacent its upper side on a rod 5l (Fig. 1) carried by the stationary block 23. The lower side of the block 66 is provided with means for releasably locking and latching it in its closed position. The latching mechanism includes a pair of hooks 68 which are adapted to catch under a bar 10 (Figs. 2 and 7) extending between the side plates 25--25 land supported thereon by means of end plates 'II-1l. The hooks 68 do not engage the bar itself but do engage a work-hardened plate 12 which is secured thereto by stud bolts 13-13. In order to compensate for wear,l a shim 'i4 (Fig. 17) of suitable thickness may be inserted between the bar 'iii and the plate l2.

The hooks 58 have integrally formed hubs 15 which fit over collars 'I6 (Fig. 8) which are eccentrically mounted on a rocker shaft 'll journaled at opposite ends in bearings 18--18 formed integrally on the cover 56. In order to turn the shaft il, a pair of spaced arms 'H9-'19 are rigidly mounted thereon and have a handle 69 supported between the outer ends thereof.

It will be seen from Fig. 8 that when the handle 69 is rotated upwardly from its closed position, the eccentrics 16 rst move the hooks l!) so as to free them from locking engagement with the plate l2. As soon as the hooks 68 are free, the entire female die unit may be swung up as shown in broken line in Fig. l.

When the female die 55 is closed, it should be exactly parallel with the male die 4D. The parallel adjustment is obtained by means of bolts 59-59 (Figs. 2 and '7) carried in the top of the cross bar i8. These bolts 58 are adjusted so that the heads thereof support the cover block 66 when closed in position which brings the female die parallel to the male die 40. Lock nuts 49-49 lock the bolts 59 in place.

In order to stop and also to position a carton released into the press 5 by the gate l I, a carton stop or catch mechanism is provided therefor which takes the form of a series of spaced, downwardly extending, blades or fingers Slidepending from a shaft 8l extending along one side of the female die block 65 and supported at opposite ends by means of a pair of side arms 82-82. Slot openings are provided in the adjacent side of the female die block 65 so as to permit the raising of the fingers 86 which fit within the slots as shown, for example, in Fig. 2. The iin-u gers 50 are shown in their lowered position in Fig. 3.

The side arms 82-82 are supported at their rear end on opposite ends of a rock shaft 83 journaled in the side plates 25-25. A crank arm 84 is integrally connected with one of the side arms 82 and projects upwardly therefrom as shown, for example, in Figs. 2 and 3. A tension spring 85 having one end connected to the crank arm 84 and the other end connected to the block Z3 as shown in Fig. 2 normally biases the fingers B0 to their lowered position when the side arms 82 are free to rotate.

The upper en-d of the crank arm 84 is in the form of a catch 86 adapted to be engaged by a catch or hook 8l formed on one of the arms of a bell crank lever 88 pvotally mounted on a supporting pin 95, as shown in Fig. 2. The bell crank lever 38 is normally biased in a clockwise direction (Fig. 2) by means of a tension spring 9| thereby causing the catch 8l to engage hook 86.

The upwardly projecting arm of the bell crank lever B8 is provided with a side pin 92 which extends through a slot opening in one end of the member 20. The slot opening has an elongated lower section indicated at 94 and a shorter upper section indicated at 93. Due to its weight alone,

7 the member 20 is ordinarily in its lower position with the pin 92 resting against the upper side of the shorter slot opening 93 as shown in Fig. 2.

Thus, when the `connecting rod I2 is pushed down so as to raise the front end I3 of the gate -I I,`the bell crank lever ["6 will be rotated counterclockwise as shown in Fig. l and will shift the member 20 toits upper position. The right-hand 'end of the shorter slot section 93 will engage the pin 92 and in turn rotate the bell crank vlever 88 in a vcountercloclwrise direction lagainst the force of the spring SI so as to thereby lift ltliercatch 81 and trip the mechanism for holding 4up the carton stops-or fingers 88.

As will appear more fully hereinafter, there are conditions yunder which it is not vdesired to have the iingers 88 lowered even though the Vgate II is raised and an egg carton is allowed to pass into the press. Accordingly, an arrangement is provided for holding the lever or member 2li in its upper position under such conditions so that the side pin S2 on the bell crank trip lever 88 is located in the elongated and lower slot section 911. This slot section is long enough so that even when the member `2i) is shifted to its uppermost position. the bell crank lever 88 will 'not be tripped. The mechanism for swinging and hold ing 'the "member 2Q in its outer position consists of a solenoid unit 95 mounted on the upper block 23 by means of a bracket 816. The operating member 87 of the solenoid connected at its bottom `end'to a link 8B, the bottom end 'of which is provided Vwith a slot 108 which ts over a pin lill projecting from the side of the member 2B. When the operating member 91 is in vits projected and non-operative position, the length of the slot 'IEB 'is such that the 'pin I'GI is not engaged. However, when it is des'ired'to swing the member 20 so that it can 'no longer bring about the tripping 'of the carton 'stop'ngers '80, the operating member 'el is retracted so 'that the bottom end of the slot ll engages the pin IQI and swings 'the member '25J to the point where .the Ipin 82 .rides in the elongated slot section 83.

Reference is now made to Fig. of the drawings for a description of the control means for operating the carton finishing pres-s 5. In that figure, the press .5 is shown diagrammaticay including: the ieinale die 465; the male die titl; the toggle linkage 32; and, the hydraulic cylinder '25. The upper end of `the operating rod i2 is shown connected to acrank arm IIl2 which 'is secured to one end of a shaft m3 driven by the stripper mechanism of the molded pulp egg carton forming and drying machine and apparatus. The shaft 103 may be a special shaft which 'serves as 'a timer shaft for supporting the crank arm ID? and a 'pair 'of cam-carrying wheels Ill 'and it. Each of these Wheels carries on its periphery a cam 186 and IIl'I, respectively,

- which upon rotation of the shaft |03 'in Vturn engage with and 'close lspring contacts Iilii and i lil, respectively, of switches II 'and I'I2. Preferably, the Switches "I ii 'and II2 are microswitches and these are normally open but 'are adapted to be closed momentarily upon depression -of the contacts |88 and vI'l as they are engaged by the closing'carns YIt and Ill?, respectively.

'zt-conductor -I'I3 is interconnected between one of the two terminals of the microswitch l II and a. conductor I M. "The conductor -II`4 isconnected at one lend to one terminal -I I5 of a single pole switch Hi8 having a lmovable blade or contact IIB.. At the vother end, the conductor I H is con- 8 'nected to one terminal of a solenoid unit H1 forming part of a double-acting solenoid valve IIB which controls the operation of press 5 as will be set forth below. The second terminal I2Il oi the single pole switch H9 is connected by a conductor i'2I with a source-of energization such, for example, as 110 Volt alternating current source which is shown diagrammatically at E22.

'The second terminal of the microswitch III is connected by a conductor 23 to vthe conductor 'I2I. The second terminal of the solenoid unit II'I is connected by a conductor I2l to the opposite terminal of the current source |22 `from that terminal to which the conductor l2! is connected. it will y'thus be seen that when the microswitcli -l H is closed, the solenoid unit iI'I will 'be energized by the current source E22.

The double-acting solenoid Valve 'H8 has a second solenoid unit vIE5 and one terminal of this unit is connected by a conductor I2@ -to the conductor |24 and is thus interconnected with one terminal of the current source 22. Ordinarily, the conductor 122i will be connected to the ground terminal of the current source. The other terminal of vthe solenoid unit 25 is connected by a conductor 21 to one of the terminals of the 'inicroswitch II?. The other terminal of the 'microsiv'itch H2 is connected by a conductor 28 to a terminal 38 of a ysolenoid operated, doublepole, double-throw switch indicated generally at iSi. In addition to the kterminal 33, the switch -i-i includes terminals I32, l33 and i3d. The movable operating member 35 of the switch ISI carries contacts Itand i3?. When the member ISES is in its upper position, the contact SSS vengages and closes a circuit between the terminals I3@ and ISE. When the member i is in its alternate or downward position, the contact IS'I engages and closes a circuit between the terminals iSS and 238. The terminals 43? and I3@ are connected in Acircuit relationship with the conductor I2! by means of a conductor ISB.

The `solenoid unit tilt of the switch ISi has two terminals ifli and M2. The terminal MI is interconnected with the conductor AZi by means of aconductor M3, While the terminal lt is vcon nected to the conductor IM by means of a conductor EM.

@ne of the two terminals 'of the solenoid unit is connected by a conductor |45 to the terminal ISS of the switch i 3 I. The second terminal 'of the solenoid unit '85 is connected by a con- -ductor N35 tothe conductor 124.

The double-acting solenoid valve unil; H8 is supplied with oil or Vother hydraulic iiuid under pressure through a supply line liti which con nects with a supply pressure pump Ill. In the supply line M1 a manually operable control' valve 'Idis located whiclrcan be adjusted so as to regulate the rate at which the hydraulic fluid is supplied to the unit IIB so as to in turn control the speed with which the press 5 operates. The puro-p 'i158 is driven by an electric motor i5! with the motor and pump unit being mounted on a suitable base E52. The fluid return line from the unit kH8 is indicated at `I'53. Ordinarily the pump will operate continuously and excess pressure in the supply line '58 is relieved by means of a lrelief valve it located therein and discharging into the return line IS through the Aconnection 55. Hydraulic iiu'id to operate and 4close the Acarton'press is supplied to 'the pressure cylinder 26 from the 'double-acting solenoid Valve unit H8 through a 'supply line IE6. IThe line l also servesas a `return line when the press is opened and the piston within `the cylinder 26 is retracted. The hydraulicfluid under pressure for opening the press is supplied to the opposite end of the cylinder 26 by means of a` supply line |51. The line |51 also serves as a return line when the press is closed.

In operation: In normal operation the shaft |03 (Fig. 5) will be driven and rotated along with the stripper mechanism which serves to strip the dried molded pulp egg cartons from the conveyor by which they are carried through the drying tunnel. The drying tunnel and the stripper form portions of the over-all automatic apparatus for forming the molded pulp cartons from wet stock or pulp slurry. Upon each rotation of the shaft |03, the connecting rod or link |2 is reciprocated so as to operate the carton control gate I in the chute section 6, rst to the open position and then to the closed position. In the open position, the gate II allows one of the cartons 8 to slide down into the press 5 which is in the open condition with the dies separated. At the same time, the rear projection |4 on the gate holds back any cartons 8 that may remain in the chute6 above the gate.

Each carton slides down into the press 5 and rides in on the side guides or rails 51-51 which are in their inner position as shown in Fig. 3. At the time the gate I is raised, the connecting link is moved up and serves to trip the catch 81 which holds up the stop mechanism for the press 5. When this mechanism is tripped, the spring 85 causes the stop members 80 to be lowered to their position as shown in Fig. 3 where they obstruct and arrest the movement of the carton as it drops or slides into the press 5.

The cam projection |01 on the wheel |05 (Fig. 5) carried on the shaft |03 leads the cam member |06 on the cam wheel |04 by a suitable number of degrees so that as the shaft |03 rotates the cam |01 will rst engage the contact member ||0 of the microswitch ||2, thereby closing this switch momentarily until the cam member |01 disengages the contact member I |0.

Closure of the microswitch 2 serves to energize the solenoid unit which is the unit which operates the double-acting solenoid valve 8 in such a way as to supply the hydraulic uid under pressure through the line to the rear (e. g. bottom) 0f the pressure cylinder 26. The solenoid carton stop controller switch |3| is normally positioned where the contact member |36 engages the terminals |30 and 32, thereby completingr the circuit between the microswitch II2 through the conductor |28 and through conductor |38 which is connected by conductor |2l to one of the terminals of the current source |22. The other terminal of the current source |22 is connected through conductors |24 and |26 to the other terminal of the solenoid unit |25.

When the hydraulic fluid under pressure is thus admitted to the base of the pressure cylinder 26, the piston of the cylinder is forced out (i. e. up) so as to raise the block 36 of the press 5 by means of the toggle connection. As the block 36 is raised, the four posts 31-31 are lifted and carry upwardly on the upper ends thereof the block 38 on which the male die 40 is supported. The compression springs 50 cause the block 45 to follow the block 38 for a portion of the upper movement of the latter. As the block 38 moves up, the cam rollers 6| are forced out as they follow the cam tracks 62 of the members 63. In turn, the arms 58 supporting the carton guide or support rails 51 are moved out to the position in Fig. 4. The block 38 continues to rise until the carton 8 to be pressed is firmly pressed between the male die 40 and the female die 65 which serves to arrest the final upward movement of the male die 40;

The cam member |06 is so positioned on the cam wheel |04 (Fig. 5) that shortly after the press has been closed the cam member |06 engages the contact member |08 of the microswitch thereby closing the same. At this time the cam |01 will have already disengaged the contact member ||0 of the microswitch ||2 and this switch will be opened. When the microswitch I is closed, the solenoid unit |1 of the double-acting solenoid valve I8 will be energized from the current source |22 and the unit |8 will be operated so as to deliver the hydraulic iiuid under pressure through the line |51 to the upper side of the piston and the pressed cylinder 26. Hydraulic fluid will be discharged through the line |56 and returned through the line |53 to the pump |48. The piston is retracted in the cylinder |26 and the press block 38 is thereby lowered, carrying with it the male die 40. As the press 5 is thus opened, the side rails 51 are retracted to their inner position as shown in Fig. 3 and the die block 38 is sufficiently lowered so that the bottom heads 54 on the tappets 53 strike the upper surface of the lifted block 45 and cause the tappet heads to raise, therebyfreeing the carton from the maledie 40. The parts are so dimensioned r of the dieblock 38 frees the carton from the male die 40.

The upper and closing movement of the male die 40 serves to reset the carton stop mechanism including the stop fingers -80. That is, the fingers 80 are raised and the side arms 82 are pivoted around the shaft 83 so that the hook 84 is again engaged and held by the hook or catch 81. The pressed carton is thereby allowed to slide out of the press into chute section and onto the conveyor I0.

The above completes the cycle of the operation which is repeated during the operation of the machine.

There may be instances in which it is desired to open the press 5 or to keep it open while the carton making machine is in operation. The manually operable switch I9 serves as an emergency or control switch for this purpose. It will be seen that when switch ||9 is closed, the

solenoid unit ||1 of the unit |v| 8 is energizedl and serves to open the press in the manner described above and to Ihold it open so long as this unit is energized. At the same time that the switch 3 is closed and energizes the solenoid unit |1, it will also be seen that the solenoid |40 is energized and the switch |3| is operated so that the contact member |36 disengages the terminals |30 and |32 and the contact member |31 establishes a circuit between the terminals |33 and |34. The closing of the latter contacts serves to complete the circuit to the solenoid unit and this unit serves to lift the operating link 20 as described above so that the elongated slot 93 is engaged by the pin 92. Thus, the member 20 can continue to reciprocate without tripping the stop mechanism which includes the stop fingers or prongs 80.

It will be noted that so long as the switch |I3 remains closed, the circuit tothe solenoid unit v|25 of the press controlvalve cannot be closed and it is impossible for. the press. to be closed.

accidentally.

Preferably oneor bothof the press dies is heat-v ed. in order to. obtain a. better pressing. action.

That is, a carton can be squared up faster and given a smoother nish. when, at least one of the dies is heated. The die maybe heated either electrically or by means of a circulating hot lluid. such as steam or oil` The particular details of.

the` heating arrangement are not importantand any suitable known arrangementmay be'made. The temperature should be high-but without dan,- ger of scorching orf-burning the molded pulpcartons.V In Fig. the female die 65 is shown with inlet and outlet connections 15b and ll through which steam or other heating medium. mayv be introduced intoandwithdrawn from the hollow. interior ofthe die block.

It will be understood that certain-changes and modifications of a detail design nature may be made in the embodiment of the invention describedv above in connection with the accompanying drawings without departing from the spirit and scope of theinvention. For example, modiiications may be made in the electrical control circuits and theL control systems for operating the press 5. The mechanicallinkagesfor operating the carton gate l| and the carton stops 8@- maybe replaced with electricallyor hydraulically operated mechanism. Other variations of like naturewill be apparent and Voccur to thoseskilled inthe art.

The invention also is applicable to molded pulp machines upon which the molded articles aredried on an open belt which does not require a stripper mechanism." In this type machine the molded articles come through" the drier in processional relationship and fall into thel chutes leading to the presses; Thereafter; they-are timedarticles adapted to be located in a discharge chutefor said articles and comprising: a female die and a maladie-at least one of which is movable,

means for opening and closing said dies, article support members reciprocally mounted formove ment intoopposite sides of thefppening formed between said dies when thesame are opened so as to form continuations of' saiddischarge chute, and means operatively connecting said support members with the movable die to remove said article Vsupport members from said opening as said dies are closed and tomove said members into said opening as said dies areopened;

2. In combination, a finishing press for-molded pulp articles comprisingaiemale die and a male die at least one of whiohis movable, means for openingand closingsaid dies operatively connected therewith, article support membersreciprocally mounted on opposite sides ofthe opening formed between said diesv whennthe` same are opened, means operatively connecting said support members withone of'saiddieswhichis movable to remove said.' support members from said opening between said dies when the latter are being closed together and to move said. support members into' said opening when said dies are being separated, an upper chute section for molded pulp-articles the bottom end of which is positioned to discharge articles onto said article support members when located in said opening formed between said dies, and alower chute section for molded pulp articles the upper end of which is positioned to receive articles discharged from between said dies.

3. A nishing press for pressing molded pulp articles comprisinga female die, amale die, stationary support means for one of said dies, movable-support means for the other one of said dies, actuating means operatively connected with said movable support means for alternately closing said movably. supported die against said station-- arily supported die and retracting it therefromso as to provide anopening between said dies, a pair ofarticle support rails, support arms. for each of said railspivotally mounted on` a4 i'lxed portion of said finishing press, andv actuating means operatively interconnectingsaid-rail support arms with saidv movable diek support means to swing said support rails` into article supporting relationship within said openingY between said` dies when the dies are separated and swingable out of said openingwhen said dies are closedv together.

4. The molded.. pulp. article iinishing press called for inclaim 3 whereinsaidactuating means for said article support rails comprises, a cam follower mounted. on each of said rail support arms, and fixtures having cam tracks for said cam followers mounted onsaid movable die supportr for operating engagement with said cam followers.

5. A nishing press for pressing molded pulp articles and adapted to be located between upper and lower sections ofA agravity discharge chute .for saidarticlcs, comprising, a stationary die supporty a die-mounted on said stationary support,

a stationary block spaced away from and parallel to said stationary die support, a movable' die support carried on; connecting rods projecting through said stationary block; a mating die )for said stationarily mounted die mounted on said `movable support, a follower'plateslidably mountedon'said connectingfrods intermediate said stationary block and said. movable die support, a plurality of guide bolts extendingr through openings prcvided therefor-in said follower plate with the ends. of said -bolts being secured to said stationary block andthe heads of said bolts located intermediate said follower plate and said movable diesupport, compressionsprings surrounding the Shanks of said guide boltsv and compressed between said stationary block and said follower so as to force. said follower plateaway from said stationaryblock and to follow said movable die support, said bolt heads beingv located so as to arrest the following movement of said .follower plate beforesaid movable die support closes said movabledieagainst said stationary die, a plurality of headed tappets extending through said movable die and said movable die support with the heads disposed toward said followerA plate, compression springsv tting around each of'said tappets and compressed between said movable die support andfsaid tappet heads so as to hold said heads inv contact with the adjacent face of said follower plate and away fromv said movable die support, said tappets being of such length. that the ends thereof projecting through said movable die will be raised sufficiently to free a molded article therefrom whensaid movable die support occupies its closest relationship to said follower plate and ofsuch length as not to engage o, molded article on said movable die when the following movement of said follower plate is arrested and said movablev die support separates therefrom.

6. In combination, a gravity conveyor chute for articles to be pressed, gate means mounted in said chute for restraining a line of said articles above said gate means and operable to release said articles one at a time from the bottom end of said line, a press for pressing said articles disposed in said chute posterior to said gate means and comprising a pair of pressing dies one of which is movable and one of which is stationary, article stop means having at least one article engaging linger, support means for said stop means movable between two positions in one of which said article engaging linger lies in the opening formed between said dies when they are open and in the other of which said article engaging finger is retracted from said opening, releasable catch means for said support means for retaining said finger in its retracted position, and link means operatively interconnecting said gate means and said releasable catch means to release said catch each time said gate means is opened, said movable die on its closing movement engaging said article engaging iinger to move it into its retracted position.

ALFRED E. COMSTOCK.

References Cited in the le of this patent UNITED STATES PATENTS Number Leston May 17, 1949 

